code: def default_valid_timestep(self):
      kwargs = dict(self.forward_default_kwargs)
      num_inference_steps = kwargs.pop("num_inference_steps", None)
  
      scheduler_config = self.get_scheduler_config()
      scheduler = self.scheduler_classes[0](**scheduler_config)
  
      scheduler.set_timesteps(num_inference_steps)
      timestep = scheduler.timesteps[-1]
      return timestep
  
imports: import tempfile
  from typing import Dict, List, Tuple
  import torch
  from diffusers import LCMScheduler
  from diffusers.utils.testing_utils import torch_device
  from .test_schedulers import SchedulerCommonTest
label_desc: Use image node_id 2 for calling the LCMSchedulerTest obj's underlying member method code with example usage: obj.default_valid_timestep() and returns: timestep